Elevator safety



July 24, 1928. r 1,678,031

J. N. ANDERSON ELEVATOR SAFETY APPLIANCE Filed Aug. 1'7, 1926 2 Sheets-Sheet l INVENTOR ATTORNEY Patented July 24, 1928.

UNITED STATES PATENT OFFICE.

JOHN N. ANDERSON, OF HOBOKEN, NEW JERSEY, ASSIGNOR TO OTIS ELEVATOR COM- PANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ELEVATOR SAFETY APPLIANCE.

Application filed August 17, 1926. Serial No. 129,748.

5 elevator system to a stop in the event of its traveling above a predetermined speed.

One feature of the invention is to provide a safety appliance which, when actuated, operates to apply a substantlally constant retarding force in predetermined amount to brlng a moving body to a stop.

Another feature lies in the provision of a safety appliance which, after it has been applied to stop a moving body, will be released upon movement of the body in the reverse direction. I

Still another feature is the provision of a safety appliance of the above character which is of simple construction, reliable in operation and which may be operated an unlimited number of times without replacement.

Other features and advantages Wlll become apparent from the specification, taken in connection with the accompanying drawings wherein one embodiment of the inventi on is illustrated.

In the drawings:

Figural is a schematic representation of an elevator system illustrating the adaptation of the safety appliance to an elevator car- Figure 2 is a view in partial section, taken along the line 2-2 of Figure 1;

Figure 3 is a sectional view taken along the line 3-3 of Figure 1;

Figure 4 is a view in partial section, taken along the line 44 of Figure 1; and

Figure 5 is a view in partial section, taken along the line 55 of Figure 4.

Referring to Figure 1, the elevator car is designated by the numeral 1 while the counterweight is designated by the numeral 2. Hoisting ropes 3 for the car and counterweight pass over the hoisting drum 4 at the top of the elevator shaft. This drum is driven by means of the hoisting motor 5 to effect the raising and lowering of the car and counterweight. An electromagnetic brake 6 is employed for bringing the motor, and therefore the car and counterweight, to a stop. Guide rails 7 are provided for the elevator car and guide rails 8 for the counterweight. The bottom guide shoes for the car are designated 12 while the top guide shoes are designated 13. The counterweight guide shoes are designated 14. A governor rope 15 extends around atensioning sheave 16 that has a weight 17 mounted in the guides 18 at the bottom of the hatchway. From the sheave 16 the governor rope extends upwardly and over the sheave 20 of a centrifugal governor 21. The governor 21 is of the flyball type wherein the ball carrying arms 22 are connected through links 23, sleeve 24, lever 25 and link 26 to the arm 27 of a jaw 28. Jaw 28 is pivotally mounted on a shaft 30 and is geared to a coacting jaw 31. Jaw 31 is pivotally mounted at 32 on a rod 33 that is slidably carried in a guide support 34. A spring 35 surrounds the rod 33 and urges jaw 31 toward jaw 28. From the sheave 20 the governor rope extends downwardly bet-ween the jaws 28 and 31. These jaws are arranged to grip the governor rope upon the operation of the governor 21. A spring pressed latch 36 engages the arm 27 and prevents the jaws from engaging the governor rope until the governor 21 operates through link 26 to elfect the release of this latch.

According to the preferred arrangement, the ends of the governor rope 15 are connected by yokes 37 to an arm 29 of a bell crank lever 38 pivotally mounted on a shaft 40 extending from the channel members 48 and 59 of the car frame. The other arm of the lever 38 extends upwardly and is pivotally attached to a lock bar 41 by means of a screw 39 extending through the arm and threaded into the lock bar. The lock bar 41 is carried by a releasing bracket 42 secured to the car frame. As illustrated in Figure 2, the lock bar 41 is positioned within an aperture 43 in the releasing bracket. The lock bar is of rectangular cross section and is formed with a boss 14 at one side thereof. This boss is provided with a recess 49 in which rests the cylindrical face of a releasing jaw 45. The jaw 45 extends through an aperture 46 in the releas ing bracket and is held in contact with the lock bar by a bolt 47. Bolt 47 extends through an aperture in the jaw 45, through a slot in the lock bar 41, through an aperture in the releasing bracket and through the channel member 48 of the car frame. The end of the bolt 47 extending beyond memher 18 is surrounded by a compression spring 50 having spring seats 11 and 19. This spring acting through the seats 11 and It) bears at one end against the channel member and at the'other end against the nut 51 thriaded on the bolt. By adjusting the nut 51 and cotter pin 52 along the bolt l'i', force of the spring 50 and the result sure exerted by the jaw bar 4 1 may be varied.

lilejicrring again to Figure l, a lift rod Til has its upper end attending through the a in of thebell crank lever 3%). Nuts h lfare threadedon the end of thelilt rod 5i3'ad ia- (:entthe arm 29 and serve to secure this red to the arm 29. The lower end of the lift rod ispivotally connected to a lever 55. Lever 55 is lmyedto a rock sha'lt 56 that 's sup ported in bearings 57 and 58 formed on the guide clamp housingsliO and ($1 of two guide clanipslll and'tifi. Guide elanip'housings 60 and (S1 carry the lower ,Siuide shoes 12 and are secured to the opposite ends of the safety plank 62 of the car tran'ie by means or? screws 63. A'lever 69, similar to the lever is keyed to the rock shaft odadjacent the bean ing 08.

1 Guide clamps E l-and 65am ()ffiilfilllifl construction. The constriu-tion of one of these guide clan'ips i. e., clamp 64-, illustrated in Figr'res 3. 4 and Guide clamp (l-t coinp11 ses'two jaw niein iers (l6 and 6? that are pivotally mounted on the central portion oi a' vertically extei'iding; shaft 70. A bushing; 68' is positioned between, the jaw n'ien'ibers and the sh aft 70. Jaw niei'nber 7 is formed with two pivotal lugs'i'?) and '("that encircle the bushing ($8 and extend over similar pivohillugs T5 and 76 lorn'ieil on. jaw member (56. The jaw members are retained on the shaft 'i'O by a nut '71 threaded onthe reduced lower portion of the sl'iatt and locked thereon as by a cotter pin. it washer interposed between jaw ineinbcr ti? and nut 71. The upper portion of the vivotal shall is reduced in diaine'l'er and extends through and beyond the horu-"ziug (ill. The portion ot-the sha'it 70 that eI-Jtcnd -a hi rond the housing (30 is thrcadeo and has a nut 77 thereon tor securing the shalt 'Tll rigidly to the housin A cotter pin 78 loe is the PTGFragainst the lock W the nut T'l'l'o the shaft 70.

"ihe portion oi the jaw nicu'iber tlllthat is opposite the guide rail 7 is lorn'ied with a vertically extending semi-cylindrical recss 80. "A wedge 81 having a semi-03diudrical bearing: surface eorresgionding to the recess flfi lies against the jaw member 66 within the recess '80 and is tree to swivel therein. lheinclined'surl'ace of the wedge 81 faces the guide rail '7 and isl'orined with a depression in its lower portionto contorni to th surta'ce of a roller 82 The wedgelli-is formed with a recess S tatits upper eud into wl ieh recess extends a stop plate W re- \./\l )r The step plate secured to the housing so b" screws 85. The lowerend ofthe wedge on a bin chet 86 attached by screws 87 c jaw member (56. TllGlOllGl 82 is carby trziinie tltljih otally mounted on a as to mod on the end 01 the lever 55. fra'nie iaS-comprises a pivotal pin 94 ing through the roller 82 and connected 5; eudis to twosi-de plates 90 and. 91 that lily mounted on axially aligned rows 92 and '93 threaded into the boss 96. rev; 92 also serves to connect the lift rod tolhe lever 55. Theboss 96 is cylin- "cal inform and its upper curred surlaec ibutted by the roller its this surface is concentric with the screws and 93, swinging inovei'uent o l lhe 'lranie 88 with res 'icet to the lever 55 causes the roller82 to mining); the 'e on the jaw uien'lber m ass t it rill on the surtar-e of the bossllG. The lift rod. 53 grooved: at to aeeonunodate the end o l' the pin 9- T he bracket 86 is formed with a hooked portion '97 upon which the lower surface of the boss'llli rests. A stop brael'cct 100 is E-fGLlil'GCl to the under surface 1" q'i 1 '1'} 1 0 f '1' Lil r tl r (n. the ,Wi LlelllJel )4 am. 1,, eiiace 1 1a iorizontal beveled portion 191 extending parallel to the side of the guide rail. This hevcmlf giio tion 101 engages o eside of the roller iii feud retains it away troin the guide rail and against thedower depressed surface (it the wedge 81.

The. portion of the jaw member 67 that is oppo ite the guide rail 7 is formed with a i-surilace 102 that. is inclined to the guide ail.

ji dovetail gijiideway 103 provided on toss incluied sui lac and accommodates the dovetail tongue 10!; of a releasingwedge 10:1

the tongue 101- would be eonstrhcted of some such mat i all as brass. In this case the sides of the g uidewa and the tongue secured to their r spective parts as byscrews 106. The releasing wedge 105 'l'HOY'ldQfl. with a cylindrical recess il 0'? extending parallel to the inclinedsurface o'ithe'jaw member 67 For a portion of the length ot the wedge. A l'racl-ret 'is secured to the jaw member 6? by screws l'lland has a pin 112 extending upwardly into thereeess 107. A compres sion spring- 108 surroui'ids the pin 112and extends into the recess 167. This spring s at one enda 'ainst the bracket 110 and 7" ie other end against the inner end of the recess 10*? and urges the releasing wedge 105 up. il-ldlj'. A i irojeeting webllfi is formed on jaw member 67 and is adapted to engage an abutn'lent 146 formed on jaw member 66 when the guide clamp is in disengaged position.

The ends of the jaw members 66 and 67 that are farther from the guide rail 7 have a compression spring 113 interposed between them. A spring seat 114 is interposed between spring 113 and jaw member 66 while a washer 115 is interposed between this spring and jaw member 67 A bolt 116 extends through spring seat 114, spring 113, washer 115, and an aperture 117 in jaw member 67. The head of bolt 116 extends into a rectangular recess 118 formed in the member 66 and is prevented from turning therein by engagement with the sides of this recess. The portion of the bolt 116 that extends beyond the jaw member 67 has a washer 126 and a nut 127 retained as by a cotter pin thereon. Spring 113 may be placed under no initial compression or under any initial compression that may be desired by varying the thickness of washer 115. A semi-annular web 120 formed on the member 66 at one side of the spring seat 114 and a plate 121 secured to the member 66 by bolts 122 at the other side of such seat, serve to retain the spring seat and therefore the spring in proper position on the member 66. Likewise a semi-annular web 123 formed on the member 67 and a plate 124 secured to the member 67 by bolts 125, serve to retain the washer 115 and the spring in proper position on this member.

A. lug 128 provided on the jaw member 67 is apertured and has a bolt 130 extending therethrough. This bolt also extends through and beyond an aperture 131 in an angle bar 132. Angle bar 132 is secured by bolts 13-3 to another angle bar 134extending across the lower side of the safety plank 62 of the car frame. The bar 134 is affixed to the safety plank 62 by bolts 135. The portion of the bolt 130 extending beyond the aperture 131 in the bar 132 is surrounded by a compression spring 136. Spring 136 bears at one end against the bar 132 and at the other end against a washer 137 positioned adjacent the head of the bolt. Nuts 138 and 140 and a washer 141 are positioned on the shank of the bolt 130 adjacent the lug 128 for varying the compression of spring 136. This construction serves to maintain the clamp structure as a unit against stop plate 83. Thus, stop plate 83 not only serves as means for maintaining the wedge 81 against jaw member 66 but also as a stop for the clamp structure.

In operation the car moving up and down the hatehway acts through lever 38 to cause a corresponding movement of the governor rope 15. This rope passing over the sheave 20 effects rotation of the governor 21. Governor 21 is set so that, as long as the lescending car does not exceed a certain speed,

the governor does not operate to cause the jaws 28 and 31 to grip the governor rope. In the event that the speed of the car exceeds this certain speed, the governor operates through link 26 to overcome the latch 36 and effect the release of jaws 28 and 31. These jaws, turning about their pivotal shafts, fall under the influence of gravity and grip the governor rope with a pressure determined by the force of spring 35. The motion of the governor rope is retarded causing the arm 29 of the bell crank lever 38 to swing upwardly with respect to the car. This upward movement of the arm 29 can only be accomplished, however, by the bell crank 38 pushing the lock bar 41 inwardly of the releasing bracket 42. This movement of the lock bar 41 forces the relasing jaw 45, against the pressure of spring 50, out of the recess in the lock bar. As arm 29 swings upwardly, it raises lift rod 53 and causes the lever 55 connected to the lower end of the lift rod to also swing upwardly. Inasmuch as lever 69 is connected through rock shaft 56 to lever 55, this upward swinging movement of lever 55 will cause a simultaneous upward swinging movement of lever 69. The upward swinging movement of these levers 55 and 69 causes the operation of guide clamps 64 and 65. As these guide clamps operate in a similar manner, the operation of only one of them, i. e., clamp 64 will be described.

As lever 55 swings upwardly, it carries the frame 88 and connected roller 82 upwardly also. Roller 82 leaves the depression in wedge 81 and rides along the inclined face of this wedge toward the guide rail. Upon engaging the rail 7, the roller 82 rolls thereon and swings the jaw members as a unit about the shaft 70, thus moving the releasing wedge 105 into engagement with the guide rail, whereupon further movement of the member 67 is prevented. Continued upward movement of the roller 82 causes an increasing compression of the spring 113 and a corresponding increase in the frictional force of the roller 82 and the releasing wedge 105 upon the guide rail. On approaching the upper end of the wedge 81 the roller 82 strikes the stop plate 83 and can no longer move upwardly with respect to the wedge and hence cannot further compress the spring 113.

The guide clamp thus grips the guide rail with a predetermined elastic force, causing the dissipation of the kinetic energy of the car. The car is caused to come smoothly to rest, in a suitable distance, and without excessive deceleration. Inasmuch as the roller rolls on the guide rail and slides againstthe wedge 81, it does not abrade the guide rail. Owing to the freedom of the roller engaging wedge to swivel in the jaw memher and the elasticity of the spring urging the jaw member:against theiguideirail, the guide clamp automatically adjusts itselfito any unevenness et thenguide rail.

'll hen it is desired "to release the guide clamp trout theguide rail, it"isonly necessary to energize the hoisting unotor 5 so as tomrove the carin the updirection. As" the ca r starts to move Lint the 1 up direction, r the releasing wedge 105 remains stationary .on the guide rail, owing to? the I frictional ft'orce between the wedge and-the guidezrail. :It is to be noted that the angle oi-the inclined surface of the'wedge lllfi must :be sntlicient to A permit this wedge toislide with :respect to the jaw member. Furthermore the angle niust'not be so great that'the wedge will slide on the jawfiduri ng theiaptilication of the safety appliance. It :has been found that a suitable angle for wedge 105 lies between "eight degrees and fifteen degrees. The surtacelOQ oi? the jaw 1nember67 slides upwardly along the inclined. surface of the releasing wedge and toward the guidearail, causing the: member 67 :to turn about the shattTO. The springilOS is thus compressed between the releasing wedge and. the bracketl1l0 by this movement of the member (37 with respect tothe releasing wedge. The swinging rniovement otthevj aw :member G? pern'iits'the spring 1.18 toexpand, causing a din'iinution in the force exerted by the roller 82: against the guide rail. Theittrictional forces exerted upon the roller '82 byithe wedge 81 and the guiderailiareathusreduced,permitting this IOllBl'IhO-LOll 71113011 the guide rail and slide alongithe wedge 81 a way from the'stop plate 83. This motion of the roller 82 by permitting further expansion of the spring .113 eausesa correspond'ng reduction in the force exerted by the roller against the guide rail. As the roller comes to rest between the stop bracket- 100 and the depressed loweruportion ot the wedge 81, the frictional force exerted by thegulde rail upon the relcasingwedge-105 will be eliminated. The compressedcspring 12-36 acting uponthe jaw member 67,.through the anedium of bolt i130, noW=icanses this member to swingabout the shatti'ZO undefiects theseparation of the releasing wedge from therguide rail. Asi thiswedge moves from theguide rail, the compl'essed:spring 108 expands, causing thefreleasing wedge to slide upwardly along'the surface 102 of the jawr meinber 67 untilthe upper endof this wedge abuts the housingGO.

The guide clamp-is new in'its disengaged position. The manual resetting of jaws 28 and 31 of the governorQl andthe replacing ot the releasing jaw 45 within therecess49 ol the lock bar l1, places the wedgecla'inp in condition for anotherioperation.

Sincethe roller 82 is secured by the frame 88 to the lever this roller cannot escape from the guide clamp.

newest The safety clamp 1 may beioperated: many tames withouta the" necessity of? replacing any parts of either the safety appliance or of the elevator apparatus.

This safety appliance mayequallyras well be applied (to the icouaiterweight rand athus prevent'excessiveicar speedzin theiup direction.

As many xchanges" could be DTIELdG; in the above -aconstruction and many apparently widely different :wembodiments of this invention could be"niadewithout *departiingifrom the scope thereof, it is intended that all'matter contained in lthe 'abovewdescription or shown in the accompanying drawings shall be interpreted as i illustrativeaand. not in limiting sense.

lVhat: is claimed is 1,1 In: an elevator system a :body Tmoifiable in thehatchway; guide rails torrsaid 'movable body aarndi aneans carried by i the vmovable body tc r gripping tl1e -guicle=1:ails,- said gripping vmeans comprising jaw members; means ;.associated with certain: :OfeSElltl jaw members tor-effecting anwengageinent between? the jaw lIleIIlbQLSr'lilCli the guide rails and means.xassoeiated with others -otisaid jaw anembers for effecting the release of said: jawfiinembers from the guide rails.

a 2. @1111 an 4 elevatorisystem a body movable in :theuhatchway ;Jguide Jl'lllS for said movablezbody; land-means carriedby the movable i body for gripping the. :guide rails; said gripping means comprising jaw members; meansassociated avithcertain of said jaw members itor effecting an @engagement between theaw: members and: thev guide rails with said body umov-ing :in one direction; and aneans associated with otheriot saidijaw members for effecting the release of saidj aw ineinbers trom'the' guidevra-ilswupon movement ot-said body inthe other direction.

3. In an elevatorsystemya body anovable in thehatchwayuguidewrails for said movable body; and means carried by themovable body for grippingtheguide rails said gripping means comprising i jaw winembers, antit'riction means for eltecting-a1nengageinent betw'een the jaw zinenibers and the guide rails land wedgetmeans ltor; eifecting the release of --Stl(l jt\VJYiQlllbGFS tromthe guide rails.

54. In an elevator-system; .:a;;guide rail; a body movable along'said guide rail; and a safety appliance!tor said movable bodycomprising, ia housin carried-by: said movable body, tlVOqjfl-W n'iembers pivotally carriediby said housing and arranged at. oppositesides of said guide rail a roller positioned: between one jawameinberianda lside of the guiderail and 'li'lGVibblG Wlbl] respectzto'the jaw memberya wedge positioned between the second awi aneinber and the other-side er the guide rail and movable with respect' tosaid secondjaw member. I

5. In an elevator system; a guide rail; a body movable along said guide rail; and a safety appliance for said movable body comprising, a housing carried by said movable body, two jaw members pivotally carried by said housing and arranged at opposite sides of said guide rail, a roller positioned between one aw member and a side of the guide rail and movable with respect to the jaw member, a wedge positioned between the second jaw member and the other side of the guide rail and movable with respect to said second jaw member, mechanism for moving said roller with respect to the first jaw member to effect the operation of said safety appliance, motive means for causing said Wedge to move with respect to the second jaw member to efieet the release of said safety appliance, ands ring means for resisting the movement 0 the wedge with respect to the second jaw member.

6. In a safety appliance for elevators; a housing; a jaw member pivotally mounted on said housing and arranged to cooperate with one side of a guide rail; and a wedge member positioned between the guide rail and the jaw member, said jaw member and said wedge member moving as a unit to cause the wedge member to engage the guide rail upon the application of the safety appliance and said wedge member moving with respect to the jaw member to disengage the guide rail upon the release of the safety appliance.

7. In a safety appliance for elevators; a housing; a jaw member pivotally mounted on said housing and arranged to cooperate with one side of a guide rail, said jaw member having a guideway; a wedge member positioned between the guide rail and the jaw member, and having a tongue extending into the guideway of the jaw member; spring means for positioning the wedge member with respect to the jaw member; and a second jaw member pivotally mounted on the housing and arranged to cooperate with the other side of the guide rail.

In testimony whereof, I have signed my name to this specification.

JOHN N. ANDERSON. 

